Effects of speech passage duration on talk test response

Abstract

The Talk Test (TT) is a simple technique for prescribing exercise training intensity, based on the ability to 'speak comfortably' after reciting a standard speech provoking stimulus. Purpose: This study compares the duration of the speech provoking stimulus on Power Output (PO) at standard TT speech comfort markers (Last Positive (LP), Equivocal (EQ), Negative (NEG). Methods: Eighteen healthy subjects performed incremental (25W/2 min) exercise with gas exchange to measure ventilatory (VT) and respiratory compensation (RCT) thresholds. They also performed incremental exercise (random order) while repeating a standard speech provoking stimulus (31 words) 1x, 2x or 3x to allow identification of LP, EQ & NEG. The PO at LP, EQ & NEG, in relation to the PO at VT & RCT were compared. Results: The relationship between PO@VT vs LP1,2,3 (r=0.73, 0.65, 0.56) and EQ1,2,3 (r=0.74, 0.65, 0.56) and RCT vs NEG1,2,3 (r=0.78, 0.80.0.71) were reasonably strong. The mean error for predicting PO@VT was smaller with longer speech passage durations for LP1,2,3 (11.22+29.67, -11.00+34.17, -24.89+34.65 W), for EQ1,2,3 (36.22+29.67, 14.00+34.17, 0.11+36.65 W), and for NEG1,2,3 vs RCT (17.94+24.83, 11.00+23.23, -0.11+28.95 W). Conclusion: The results suggest that longer duration speech passages (9.6 vs 19.9 vs 28.7s) optimize TT vs gas exchange identification of VT & RCT.